8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P4.60Fri 911:10-14:00Anomalous structure and scaling of ring polymerbrushesPeter Virnau, 1 Daniel Reith, 1 Andrey Milchev, 2 and Kurt Binder 11 Uni Mainz, Im Staudinger Weg 7, 55099, Mainz, Germany2 Bulgarian Academy of Sciences, Sofia, BulgariaA comparative simulation study of polymer brushes formed by grafting at a planar surface eitherflexible linear polymers (chain length N L ) or (non-catenated) ring polymers (chain length N R =2N L ) is presented. Two distinct off-lattice models are studied, one by Monte Carlo methods, theother by Molecular Dynamics, using a fast implementation on graphics processing units (GPUs).It is shown that the monomer density profiles ρ(z) in the z-direction perpendicular to the surfacefor rings and linear chains are practically identical, ρ R (2N L , z) = ρ L (N L , z). The same applies tothe pressure, exerted on a piston at hight z, as well. While the gyration radii components of ringsand chains in z-direction coincide, too, and increase linearly with N L , the transverse componentsdiffer, even with respect to their scaling properties: R gxy (L) ∝ N 1/2L , R gxy (R) ∝ NL 0.4 . These propertiesare interpreted in terms of the statistical properties known for ring polymers in dense melts.60